• Title/Summary/Keyword: 이동 경계

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Numerical Modeling of Circulation Characteristics in the Kwangyang Estuarine System (광양만 권역의 해수순환 수치모델 실험)

  • Kim, Baek Jin;Ro, Young Jae;Jung, Kwang Young;Park, Kwang Soon
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.26 no.4
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    • pp.253-266
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    • 2014
  • The ECOM3D is used to study the circulation characteristics and density current from the Sumjin River runoff in the Kwangyang Estuarine System, South Sea, Korea. Annual mean value of $120m^3/s$ was imposed from the Sumjin River. The numerical model results in terms of tidal height, current and salinity field show satisfactory with skill scores over 90%. The current velocity showed the range of 1~2.5 m/s during flood and ebb phases. In particular, very strong flow occur in the narrow Channels of Noryang, Daebang and Changson exceeding over 2.0 m/s. The tidal residual currents in the various locations in the Kwangyang Estuary showed the range of 1~21 cm/s, The density-driven current through the Yeosu and Noryang Channels are about 12 cm/s and 4 cm/s, respectively. The current path through the Yeosu Channel is deflected toward west Bank. Based on budget analysis of the volume flux, the volume flux through the Yeosu Channel and the Noryang Channel were estimated to be 97.4 and $22.1m^3/s$ accounting for the 81.5% and 18.5% of total flux, respectively.

비대칭적 표면 위에 초미세 박막의 미시적 성장구조

  • 서지근;신영호;김재성;민항기
    • Proceedings of the Korean Vacuum Society Conference
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    • 1999.07a
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    • pp.187-187
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    • 1999
  • fcc(110) 표면이나 bcc(110) 표면과 같이 2-fold 대칭성을 갖는 표면 위에 초미세 박막을 성장시킬 경우 토대표면의 두 방향에 대한 비 대칭성으로 흡착물이 비대칭적인 cluster 형태로 성장되는 것이 보고되고 있다. 최근 STM에 의한 Ps(110) 표면 위에나 Si(100) 또는 W(110) 표면 위에 성장 실험은 흡착물이 길게 늘어선 한 줄 형태의 성장 또는 가로 세로가 비대칭적인 cluster 형태로 성장되는 것을 보고하고 있고, 이러한 특정 형태의 성장의 원인으로 흡착 원자의 방향에 따른 분산 속도의 비대칭성, 인접 원자와의 비대칭적인 상호작용, 또는 cluster 경계 방향의 분산 속도 등을 들고 있다. 그러나 아직 대부분의 물질계에 비해 흡착원자의 분산속도 또는 분산 장벽에 대해서는 잘 알려져 있지 않다. 원하는 원자 단위 구조물 제작을 위해서는 흡착물의 분산속도에 대한 이해가 필수적이며, 본 연구는 KMC 시뮬레이션과 실험 결과를 비교하는 방법을 통하여 위치와 조건에 따른 각각의 분산 속도를 구하고자 하는 시도이다. 특히 비대칭적 토대 위에서의 나타나는 다양한 형태의 미시적 성장구조에 관심을 가지며, 연구 방법으로는 KMC 시뮬레이션을 이용한다. 미시적 성장 양식은 분산 장벽 형태에 의해 크게 결정된다. 분산장벽 중에서 성장에 비교적 큰 영향을 미치는 것으로는 테라스 위의 원자가 이동할 때의 분산장벽인 Ed, 계단 끝에 부착된 원자가 분리될 때의 장벽인 Ep, 그리고 위 테라스에서 계단 아래로 떨어져 내려갈 때 만나는 Schwoebel 장벽들이 있다. 먼저 대칭적인 fcc(100) 표면 위에서의 성장 구조를 정리해보면 분산 장벽에 따라 다양한 미시적 성장형태를 볼 수 있었다. 다층 성장의 경우도 그 양식은 sub-ML 성장과 동일한 형태를 가지므로 sub-ML 성장구조로 전체 성장 양식을 예견할 수 있다. 일반적인 경향은 Ep가 커질수록 fractal 성장형태가 되며, Ed가 적을수록 cluster 밀도가 작아지나, 같은 Ed+Ep에 대해서는 동일한 크기의 팔 넓이(수평 수직 방향 cluster 두께)를 가진다. 따라서 실험으로부터 얻은 cluster의 팔 넓이로부터 Ed+Ep 값을 결정할 수 있고, cluster 밀도와 fractal 차원으로부터 각각 Ed와 Ep값을 분리하여 얻을 수 있다. 또한 다층 성장에 대한 거칠기(roughness) 값으로부터 Es값도 구할 수 있다. 양방향 대칭성을 갖지 않은 fcc(110) 표면과 같은 경우, 형태는 다양하지만 동일한 방법으로 추정이 가능하다. (110) 표면의 경우 nearest neighbor 원자가 한 축으로 형성되고 따라서 이 축과 이것과 수직인 축에 대한 상호작용이나 분산 장벽 모두가 비대칭적이다. 따라서 분산 장벽도 x-축, y-축 방향에 따라 분리하여 Edx, E요, Epx, Epy 등과 같이 방향에 따라 다르게 고려해야 한다. 이러한 비대칭적인 분산 장벽을 고려하여 KMC 시뮬레이션을 수행하면 수평축과 수직축의 분산 장벽의 비에 따라 cluster의 두께비가 달라지는 성장을 볼 수 있었고, 한 축 방향으로의 팔 넓이는 fcc(100) 표면의 경우 동일한 Ed+Ep값에 대응하는 팔 넓이와 거의 동일한 결과가 나타나는 것을 볼 수 있다. 따라서 이러한 비대칭적인 모양을 가지는 성장의 경우도 cluster 밀도, cluster 모양, cluster의 양 축 방향 길이 비, 양 축 방향의 평균 팔 넓이로부터 각 축 방향의 분산 장벽을 얻어낼 수 있을 것으로 보인다.

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Crystal growth studies of $SF_6$ clathrate hydrate ($SF_6$ 하이드레이트 결정의 성장 특성에 대한 연구)

  • Lee, Yoon-Seok;Lee, Ju-Dong;Lee, Bo-Ram;Lee, Hyun-Ju;Lee, Eun-Kyung;Kim, Soo-Min;Kim, Young-Seok;Yoon, Seog-Young;Kim, Yang-Do
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.19 no.5
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    • pp.228-236
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    • 2009
  • In this study, we investigated morphological characteristics of $SF_6$ clathrate hydrate crystals to understand its formation and growth mechanism. $SF_6$ clathrate hydrate crystals were formed in high-pressure reaction cell charged with pure water and $SF_6$ gas at constant pressure and temperature. Two-phase ($SF_6$ gas/aqueous solution) and three-phase ($SF_6$ gas/aqueous solution/$SF_6$ liquid) conditions were investigated, In both conditions, dendritic shape hydrate crystals were grown as like fibriform crystals along upward growth direction at the gas/aqueous solution interface. In the case of the reaction process of three-phase condition, when the $SF_6$ gas bubbles which were generated in $SF_6$ liquid phase due to the reduction of reaction cell pressure stuck to the gas/aqueous interfaces, the hydrate phase were appeared at the surface of the bubbles. This paper presents the detail growth characteristics of $SF_6$ hydrate crystals including crystal nucleation, migration, growth and interference.

A Study on Characteristics of Purchase Behaviors of Outdoor Wear Consumers (등산복 구매행동의 특성 연구)

  • Park, Ok-Ryun;Lee, Ji-Na;Lee, Dong-Cheol;Jin, Geum-Ok
    • 한국데이터정보과학회:학술대회논문집
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    • 2006.04a
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    • pp.267-278
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    • 2006
  • The purpose of this research is to identify differences between characteristics of purchase behavior of outdoor wear consumers, demographic variables and mountain climbing related variables. The subjects of surveys are selected among men and women consumers having experiences of purchasing outdoor wear in ages from 20's to over 50's who live in the vicinity of Busan. Data and information collected are analyzed by using SPSS Program. Results from the analysis of purchasing purpose indicates that they buy outdoor wear conducive to two similar reasons; that is, "only to exercise and enjoy mountain climbing" and "either to wear it in time of climbing mountain or everyday life," and results from the analysis of purchase frequency reveals that '$1\sim2$ times'a you is the highest. Results from analysis of preference of brand of outdoor wear reveals that Kolon Sport is followed by the North Face and K2.

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Global Citizenship Education in the Primary Geography Curriculum of the Republic of Korea: Content Analysis Focusing on the Semantic Structure of 2009 Revised School Curriculum (초등지리 교육과정에 반영된 세계시민교육 관련 요소의 구조적 특성에 관한 연구: 2009 개정 교육과정 성취기준에 대한 내용분석을 중심으로)

  • Lee, Dong-Min
    • Journal of the Korean Geographical Society
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    • v.49 no.6
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    • pp.949-969
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    • 2014
  • The purpose of this study is to analyze the share of global citizenship education in the 2009 Revised Social Studies (geography area) School Curriculum of the Republic of Korea. I selected the achievement standards of the geography domain in the fifth and sixth grades as the subjects of analysis. The chosen subjects were examined using content analysis: I used KrKwic, a Korean language content analysis tool, to analyze the content and drew a semantic network of the analysis results using UciNet/NetDraw. I found that the geography domain of the 2009 Revised Primary School Curriculum included the concepts of and factors of global citizenship education. However, global citizenship education did not account for a major portion of the curriculum, and the curriculum achievement standards were noticeably nation-state centered. Global citizenship education factors were not closely associated with to other related factors in fact, they even revealed a isolated pattern. These findings suggest that the inclusion of global citizenship education in primary geography education is limited, because the connections between global citizenship education and related contents, such as the environment, sustainable development, conflict, and cooperation, are probably impeded. Globalization accompanies the transformation of territories, identities, and the relations between nation-states and the world, although nation-states continue to play a significant role in the globalized worlds. Therefore global citizenship education, a educational trend focusing on the global community, is particularly important and is required in the geography curriculum of the global era. I expect that the examination undertaken in this study to contribute to future curriculum revisions regarding globalizatin and global citizenship.

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Rapid Chloride Penetration Test for Concrete Based on the Electrochemical Method (전기 영동법에 기초한 콘크리트의 급속 염소이온 확산 특성 평가)

  • Oh, Sang-Gyun;Park, Dong-Cheon
    • Journal of Navigation and Port Research
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    • v.34 no.10
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    • pp.787-792
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    • 2010
  • It is necessary to predict the penetration of chloride ions for designing RC construction in marine environments. However, it takes a long time to obtain chloride migration coefficients. Therefore, the rapid chloride penetration test (RCPT) is generally used to shorten the test time. But there is a difference between chloride migration coefficients determined by rapid chloride penetration tests and those based on exposure in marine environments. In this study, we evaluated the effect on the chloride ion migration coefficient caused by a change in voltage and NaCl concentration. We also compared the relationship between the chloride ion migration coefficient by RCPT and that by exposure in marine environments. As a result of the experiments, we found that there is only a small change in the experimental factors based on changes in voltage and NaCl concentration and since they are so small, we can conclude that they are in the range of experimental error and test results from chloride ion migration coefficients by RCPT and exposure were very different from each other. In the exposure experiments, when the water-cement ratio was increased, the smaller fine air gaps in concrete affected the chloride ion migration coefficient.

The Successful Application of Nuss Procedures with Modified Operative Technique (수술적 기법의 보완을 통한 성공적인 너스 술식의 적용(단일 기관 135명의 경험))

  • Kim Do-Mun;Shim Young-Mog;Kim Kwhan-Mien;Choi Yong-Soo;Kim Jhin-Gook
    • Journal of Chest Surgery
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    • v.39 no.10 s.267
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    • pp.765-769
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    • 2006
  • Background: Nuss procedure is a minimally invasive technique for correcting the pectus excavatum. But there are some limitations of correcting the complex anomaly or grown-up patients. Material and Method: we retrospectively reviewed 135 consecutive patients who underwent repair of pectus excavatum by the Nuss procedure and its modifications between November 1999 and December 2004. We analyzed the computed tomography, age on operation, operative technique, and complications. Result: We operated 135 patients of pectus excavatum during 62 months. Total number of operations about Nuss procedure is 216, including bar removal procedure of 64 cases, redo Nuss procedures of 47 cases. We modified the point of bar insertion to the hinge point, made a shoulder in the bar to prevent a displacement. And then we changed the fixation material from Vicryl to steel wire. If the patients are old, we retract the sternum during bar rotation and fixation. Until 2002, the number of redo Nuss operations were 17, complications were 23. but, after modifications, the number of redo Nuss operation were 0, complications were 2. Conclusion: This result indicates that our modifications of Nuss operation is effective, and could decrease the number of redo Nuss operation and complications.

Analysis on Pilot Survey for Cadastral Non-correspondence Arrangements (지적불부합지의 정리를 위한 실험측량 분석 연구)

  • 강태석;권규태
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.21 no.3
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    • pp.269-275
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    • 2003
  • The cadastral system which accomplishes the base of national land administration with accuracy of proper data and the cadastral maintenance quickly is agreeing with the actual place in information ages in Inundation. But even in spite of many efforts, various Problems are exposed in accuracy of the data on the cadastral maps and local situation must agree accurately from the process which propels cadastral information systems. Therefore, it must be carried out the cadastral non correspondence arrangement first of all in link of the plan which it corrects the error of existing data and computerization quickly. It summarizes the research as follows ; Cadastral non correspondence of the land boundaries on the map and actual circumstance does not agree with cadastral maps accurately, The lands which exceed the standards with the position error excess of 50cm on lil ,200 and 240cm on 1/6,000 areas on the map scale are the registration correction objectives. It is investigated that the cadastral non correspondence parcels occur in various cause and long period, the area error corrections are mainly objectives, and about 80% of the test area comes to reveal within permitted the limit of the measurement of planimetric area for cadastral survey, so it is not difficult with the fact that the compensation back which it follows in area increase and decrease and the location error correction becomes the important object fer the cadastral non correspondence arrangement projects.

Utilizing Airborne LiDAR Data for Building Extraction and Superstructure Analysis for Modeling (항공 LiDAR 데이터를 이용한 건물추출과 상부구조물 특성분석 및 모델링)

  • Jung, Hyung-Sup;Lim, Sae-Bom;Lee, Dong-Cheon
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.26 no.3
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    • pp.227-239
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    • 2008
  • Processing LiDAR (Light Detection And Ranging) data obtained from ALS (Airborne Laser Scanning) systems mainly involves organization and segmentation of the data for 3D object modeling and mapping purposes. The ALS systems are viable and becoming more mature technology in various applications. ALS technology requires complex integration of optics, opto-mechanics and electronics in the multi-sensor components, Le. data captured from GPS, INS and laser scanner. In this study, digital image processing techniques mainly were implemented to gray level coded image of the LiDAR data for building extraction and superstructures segmentation. One of the advantages to use gray level image is easy to apply various existing digital image processing algorithms. Gridding and quantization of the raw LiDAR data into limited gray level might introduce smoothing effect and loss of the detail information. However, smoothed surface data that are more suitable for surface patch segmentation and modeling could be obtained by the quantization of the height values. The building boundaries were precisely extracted by the robust edge detection operator and regularized with shape constraints. As for segmentation of the roof structures, basically region growing based and gap filling segmentation methods were implemented. The results present that various image processing methods are applicable to extract buildings and to segment surface patches of the superstructures on the roofs. Finally, conceptual methodology for extracting characteristic information to reconstruct roof shapes was proposed. Statistical and geometric properties were utilized to segment and model superstructures. The simulation results show that segmentation of the roof surface patches and modeling were possible with the proposed method.

Be Age-dating of Marine Sediments from NE Pacific (북동태평양 해저퇴적물의 Be 연대측정)

  • Choi, Hun-Soo;Kong, Gee-Soo;Um, In-Kwon;Kim, Ji-Hoon
    • Journal of the Mineralogical Society of Korea
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    • v.24 no.3
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    • pp.179-188
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    • 2011
  • In order to investigate absolute age of marine sediment in the KR5 region, northeastern Pacific, we measured the Be isotope ($^{10}Be$ and $^{9}Be$) of box core (BC08-02-13) sediment with depth. Core sediment is divided into three sedimentary facies (Facies I, Facies II, FaciesIII). Facies I mainly consists of brown to dark brown (10YR4/3) homogeneous mud with high water content. Facies II shows brownish yellow (10YR6/6) color. The unconformity is recognized at the boundary between Facies I and Facies II, Facies III consists of very dark brown (10YR2/2) mud. Many bioturbated burrows are observed at FaciesII and FaciesIII. Based on Be dating results, FaciesIII and Facies II had been deposited before 3.7 Ma and 2.3 Ma, respectively. After 2.3 Ma, the upper part of Facies II was eroded due to the change of sedimenary environment. Facies I has been deposited since 1.8 Ma. The unconformity located at the boundary between Facies I and Facies II may be driven by the envrionmental change due to the migration of Intertropical Convergence Zone.